ABSTRACT

The purpose of this research is to study the dispersion phenomena of SH-wave caused by obstacle that embedded in 2-D double-layered soil strata. Use the hybrid method (FEM accompanies with BEM) to get frequency-domain responses of SH-wave. Then with both the convolution theory and the Fast Fourier Transform technique, the time-domain responses can be obtained. According to the arrival time of diffracted wave and direct wave, the major parameters that effect the dispersion phenomena, such as different embedded lengths and source point etc. have been studied. Moreover, an appropriate sounding and analysis step will be drawn for embedded obstacle.

INTRODUCTION

Elastic wave propagating and scattering in solids have been under investigation in a wide range of fields of study, including seismology, geophysics, applied mechanics and elastodynarnics. Some of the major research contributions in the theory and analysis of elastodynamics were reviewed by Pan (1983). In the area of structural dynamics, there are interests in the response of structures subjected to impact or blast loads. Elastic wave theory explains the behavior in both near and far regions from the area of impact load. By the similar way, we can study the propagation, scattering and attenuation of elastic seismic waves to sound and evaluate the dimension or integrity of embedded obstacles such as underground household pipes, piles and slurry walls. This research mainly uses the hybrid method (FEM accompanies with BEM) to build up a numerical model to study the dispersion phenomena of SH-wave caused by obstacle that embedded in 2-D double-layered soil strata.

STATEMENT OF PROBLEM

The problem we consider here is illustrated in Figure 1, which shows the two-dimensional geometry of a rectangular embedded obstacle that is confined in a medium that could be a layered half-space soil strata.

This content is only available via PDF.
You can access this article if you purchase or spend a download.